Control arrangement for the cooling air of air-liquid-cooled internal-combustion engines, particularly motor vehicles

ABSTRACT

A control device for the flow of cooling air through an air-liquid radiator of an internal combustion engine comprising a fan frame mounted between the radiator and the fan and being part of a noise damper of the engine. A spring curtain is arranged in the fan frame between the radiator and the fan and isolates the noise damper of the radiator, except when the engine reaches high operating temperatures, which prevents the radiator from absorbing power and the engine from being directly air cooled, thus reducing the prewarming time of the engine.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention relates to a control arrangement for the cooling air ofair-liquid-cooled internal-combustion engines, particularly of motorvehicles, having an air-liquid radiator, a temperature-controlledcooling-air stopping element such as a rolling curtain, and a radiatorfan arranged in sequence behind one another in a cooling-air flow-endchannel, comprising a fan shroud, to an engine housing or engine spacein cooling-air flow direction, the stopping element in the closedposition closing the connecting openings between the cooling-air outletof the radiator and the engine housing or engine space, wherein thestopping element in its closed position and the part of the flow-inchannel connected to the stopping elements in flow direction, arecomponents of the engine housing or engine space developed as a noisecapsule, and wherein in the flow-end channel, outside the noise capsulebetween the radiator and the stopping element, a cooling-air outletopening is arranged that leads to the outside and closes in the oppositedirection to the stopping elements.

A known arrangement of this construction according to U.S. Pat. No.1,170,730 has a air blocking element that is developed as a flap shutteror rotary slide and a radiator fan that at a distance is exposed behindit in flow direction of the cooling air. As a result, the air blockingelement controls the cooling effect of the radiator. For a reduction ofthe cooling function of the radiator fan itself, this radiator fan isequipped with adjustable fan blades. The air blocking element, theradiator fan and the engine, in an open arrangement, are arranged at adistance behind one another in flow direction of the cooling air. Noisefrom the radiator fan, the engine and its driving connections as well asthe removal of heat of the engine and the radiator can spread to alldirections and therefore stress the environment and also extend thewarm-up time after a cold start of the engine.

Another known arrangement is disclosed in U.S. Pat. No. 2,703,075.

On the basis of DE-PS No. 532 730, a stopping element for the radiatoris known that is developed as a double curtain and reduces the heatdissipation of the radiator to both sides but has no effect on the noiseand heat emission of the radiator fan and of the engine.

It is the objective of an invention to further develop the controlarrangement of the initially mentioned construction in such a way thatthe noise and heat emission from the engine and the radiator fan arereduced.

As a result, the noise and heat emission, from a noise capsule that issubstantially tight to all sides, when the air blocking element isclosed, can be reduced considerably in the case of a cold engine and anengine operated at part load and thus especially always in cases whenthe noise emission especially in the case of Diesel engines isespecially high and a high, damming of heat is especially advantageousfor low wear as well as low fuel consumption and a low emission ofharmful exhaust gas substances by means of a short warm-up phase.

Another object of the invention is the provision of a controlarrangement for the cooling air of air-liquid-cooled internal-combustionengines, wherein a stopping element is developed to be largely airtightand wherein a fan has a fan shroud having a narrow annular gap that islargely free of return flow in the direction of the outer circumferenceof its running wheel. With such a configuration, when the stoppingelement is closed, largely a zero blower output of the fan is achievedso that for this purpose, despite the rigid driving connection with theengine, hardly any driving output is required and therefore theconstruction expenses of a fan coupling or an electric fan motor are notnecessary.

It is another object of the invention to provide a control arrangementfor the cooling air of air-liquid-cooled internal-combustion engines,wherein a stopping element is developed as a rolling curtain having asupporting screen that penetrates a fan shroud in transverse directionto the cooling-air flow direction and against which the rolling curtainrests in its closed position in cooling-air flow direction in order tomake possible a high density effect and smaller dimensions than those ofthe radiator.

It is another object of the invention to provide a control arrangementfor the cooling air of air-liquid-cooled internal-combustion engines,wherein a fan shroud has an approximately cylindrical shroud ring thatin cooling-air flow direction connects directly to a supporting screen,and wherein the supporting screen has a rectangular shape projectingbeyond the shroud ring, in approximately triangular areas of which,outside the shroud ring, ram-air passage openings are arranged in thefan shroud that are controlled by the rolling curtain and by ram-airflaps to permit a smaller overall length and at the same time a controlof additional ram air openings by means of the rolling curtain.

It is another object of the invention to provide a control arrangementfor the cooling air of air-liquid-cooled internal-combustion engineswherein a cooling-air outlet opening leading to the outside between aradiator and a stopping element has a return-flow flap that closesautomatically when the stopping element is open and the fan is driven inorder to extend the noise-reducing effect of the stopping element beyondthe warm-up time of the engine to operating times in which the coolingair output is sufficient without the radiator fan, especially thereforeat part load and low ambient temperature.

The operating temperature of the engine, in this case, when the airblocking element is closed, can be determined in the conventional way bymeans of a thermostat controlling the temperature of the cooling liquid.After the given cooling output is exhausted in this case, by means of atemperature switch controlled by the cooling liquid temperature, thecomponent temperature of the engine and/or the air temperature in theengine space, the air blocking element can be opened and, if necessary,the radiator fan can also be put in operation. This then will result inthe full cooling output and engine space ventilating function ofconventional radiator fan arrangements with fan shroud and engine spacenoise capsule.

Further objects, features, and advantages of the present invention willbecome more apparent from the following description when taken with theaccompanying drawings, which show for purposes of illustration only, anembodiment constructed in accordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial longitudinal section through the front part of amotor vehicle having a control arrangement according to the inventionfor the cooling air to the radiator and to the engine space; and

FIG. 2 is a partial top view of the control arrangement according toLine II--II in FIG. 1.

Referring now to the drawings wherein like reference numerals are usedto designate like parts and more particularly to FIG. 1, in the frontpart 1 of a motor vehicle, an air-liquid-radiator 3, a air blockingelement for the cooling air that is developed as a rolling curtain 4having a support screen 5, a radiator fan 6 and an internal-combustionengine 7 are arranged behind one another in flow direction 2 of thecooling air. A fan shroud 9 connects to the cooling-air outlet 8 of theradiator 3 and ends in flow direction of the cooling air 2 in a shroudring 10 that surrounds the outer circumference of the fan 6 with anarrow annular gap 11 that, when the rolling curtain 4 is closed, islargely without return flow and thus avoids producing output from thefan 6.

The support screen 5, that extends through the fan shroud 9, isarranged, in a space-saving way, directly in front of the shroud ring 10in flow direction 2 of the cooling air, the rolling curtain 4interacting with the support screen 5 for a largely airtight exclusionof a cooling air flow from the fan 6 and thus from the engine space 12and prevents or blocks a noise emission in opposite direction from theengine space 12 and through the radiator 3 to the environment. For thelatter purpose, the engine space 12 is also developed as a known noisecapsule in a way that is not shown.

The rolling curtain 4 has a wind-up reel 13 above the shroud ring 10.Between the radiator 3 and the rolling curtain 4 or the support screen5, at least one lower cooling-air outlet opening 14 having a return-flowflap 15 is arranged in the fan shroud 9, said cooling-air outlet openingleading out into the open and making possible a cooling effect of theradiator 3 for the partial-load operation of the engine 7 when therolling curtain 4 is closed. The warm cooling-air flow from the radiator4 in this case keeps the rolling curtain 4 from freezing in place andthus ensures its automatically controllable opening when a predeterminedoperating condition of the engine 7 is reached, such as high values ofthe ambient temperature, of the engine space temperature, of a componenttemperature, of the engine output and/or coolant temperature. Intriangular areas of the fan shroud 9 and of the supporting screen 5projecting beyond the shroud ring 10, ram-air openings 16 having ram-airflaps 17 are arranged that act in parallel with the shroud ring 10, saidram-air openings 16 resulting in a ram air flow that is in addition tothe output of the fan 6 and is controlled by the rolling curtain 4.

Although the present invention has been described and illustrated indetail, it is to be clearly understood that the same is by way ofillustration and example only, and is not to be taken by way oflimitation. The spirit and scope of the present invention are to belimited only by the terms of the appended claims.

I claim:
 1. A control arrangement for the cooling air ofair-liquid-cooled internal combustion engines, particularly of motorvehicles, having an air-liquid radiator, a temperature-controlledcooling-air stopping element and a radiator fan which in the abovesequence are arranged in a cooling-air flow-in channel to an enginehousing or engine space in cooling-air flow direction behind oneanother, wherein the stopping element is arranged in a fan shroudconnecting a cooling-air outlet of the radiator with the fan, the fanshroud and the stopping element are components of a noise capsule forthe engine that is formed by the engine housing space, the stoppingelement is developed to be largely air-tight and wherein the fan shroudtoward an outercircumference of the fan has a narrow annular gap meansthat is largely free of the return flow to prevent the radiator fan fromcirculating air from an exhaust area of the fan back to an inlet area ofthe fan.
 2. A control arrangement for the cooling air ofair-liquid-cooled internal combustion engines, particularly of motorvehicles, having an air-liquid radiator, a temperature-controlledcooling-air stopping element and a radiator fan which in the abovesequence are arranged in a cooling-air flow-in channel to an enginehousing or engine space in cooling-air flow direction behind oneanother, wherein the stopping element is arranged in a fan shroudconnecting a cooling-air outlet of the radiator with the fan, the fanshroud and the stopping element are components of a noise capsule forthe engine that is formed by the engine housing space, wherein thestopping element is developed as a rolling curtain having a supportingscreen that penetrates the fan shroud transversely to the cooling-airflow direction and against which the rolling curtain rests in its closedposition, in cooling-air flow direction (2).
 3. An arrangement accordingto claim 2, wherein the fan shroud has an approximately cylindricalshroud ring (10) that in cooling-air flow direction connects directly tothe supporting screen, and wherein the supporting screen has arectangular shape projecting beyond the shroud ring, in theapproximately triangular areas of which, outside shroud ring, ram-airpassage openings are arranged in the fan shroud that are controlled bythe rolling curtain and by ram-air flaps (17).
 4. A control arrangementfor the cooling air of air-liquid-cooled internal combustion engines,particularly of motor vehicles, having an air-liquid radiator, atemperature-controlled cooling-air stopping element and a radiator fanwhich in the above sequence are arranged in a cooling-air flow-inchannel to an engine housing or engine space in cooling-air flowdirection behind one another, wherein the stopping element is arrangedin a fan shroud connecting a cooling-air outlet of the radiator with thefan, the fan shroud and the stopping element are components of a noisecapsule for the engine that is formed by the engine housing space,wherein the fan shroud, between the radiator and the stopping elementhas cooling-air outlet openings having return-flow flaps, saidcooling-air outlet openings leading to the outside.
 5. A controlarrangement for the cooling air of air-liquid-cooled internal-combustionengines, having an air-liquid radiator, a temperature-controlledcooling-air blocking means and a radiator fan which in the abovesequence are arranged behind one another in a cooling-air flow-inchannel to an engine housing space in cooling-air flow direction; theair blocking means, in the closed position, closing connecting openingsbetween a cooling-air outlet of the radiator and the engine housingspace; wherein the air blocking means in a closed position and a part ofthe flow-in channel connecting the air blocking means to the radiatorfan in flow direction are components of the engine housing spacedeveloped as a noise blocking capsule means; and wherein the flow-inchannel, outside the noise blocking capsule means between the radiatorand the air blocking means, has a cooling-air outlet opening that leadsto the outside when the air blocking means is in its closed position. 6.An arrangement according to claim 5, wherein the air blocking means isdeveloped to be substantially airtight and wherein the fan has a fanshroud with a narrow annular gap between the fan and fan shroud that islargely free of return flow in the direction of the outer circumferenceof the fan.
 7. An arrangement according to claim 6 wherein thecooling-air outlet opening leading to the outside between the radiatorand the air-blocking means has a return-flow flap that closesautomatically when the air-blocking means is open and the fan is driven.8. An arrangement according to claim 5, wherein the air-blocking meansis developed as a rolling curtain and a supporting screen penetrates thefan shroud in trransverse direction to the cooling-air flow directionand against which the rolling curtain rests in its closed position incooling-air flow direction.
 9. An arrangement according to claim 8,wherein the fan shroud comprises an approximately cylindrical shroudring that in cooling-air flow direction connects directly to thesupporting screen, and wherein the supporting screen has a rectangularshape projecting beyond the shroud ring, in the approximately triangularareas of which, outside the shroud ring; ram-air passage openingsdisposed in the fan shroud in flow alignment with the triangular areas;and wherein the ram-air passage openings are controlled by the rollingcurtain and by ram-air flaps.
 10. An arrangement according to claim 9wherein the cooling-air outlet opening leading to the outside betweenthe radiator and the air-blocking means has a return-flow flap thatcloses automatically when the air-blocking means is open and the fan isdriven.
 11. An arrangement according to claim 8 wherein the cooling-airoutlet opening leading to the outside between the radiator and theair-blocking means has a return-flow flap that closes automatically whenthe air-blocking means is open and the fan is driven.
 12. An arrangementaccording to claim 5 wherein the cooling-air outlet opening leading tothe outside between the radiator and the air-blocking means has areturn-flow flap that closes automatically when the air-blocking meansis open and the fan is driven.
 13. A cooling system for a combustionengine having a radiator means accepting air input and a fan meansaccepting air output from said radiator comprising: a curtain,a screenmeans disposed between the radiator means and the fan means forsupporting said curtain, means for rolling the curtain into positionbetween said radiator and said support screen to block said air outputfrom the fan.
 14. A cooling system in accordance with claim 13 furthercomprisingmeans exhausting said air output from said radiator when saidcurtain is disposed in blocking position comprising a return-flow-flapmeans admitting passage of air from said radiator but blocking airpassage in an opposite position.
 15. A cooling system in accordance withclaim 13 wherein said support screen and said curtain are configuredsubstantially as a rectangle and said fan, during its rotation, sweeps acircle within said rectangle and further comprisingram-air passagesdisposed between said rectangle and said circle, the passages beingblocked by the curtain in its blocking position, and ram-air passageflaps disposed to block said ram-air passages when said curtain is inits blocking position.